Method of coupling a fastener on a metal sheet and forming a molded part

ABSTRACT

The present invention is a method of making a molded part having a sheet metal portion and at lease one fastener coupled to the sheet metal portion. The fastener has a body portion and an annular barrel portion which extends from the body portion. The body portion has a free open end and a bore extending therethrough in generally coaxial alignment with the opening in the barrel portion. The barrel portion free end is driven into the sheet metal to pierce the sheet metal and form a slug from the sheet metal. The barrel is also deformed radially outwardly in mechanical interlocking relation with the panel. The slug which is formed is wedged into the opening of the barrel portion to seal the barrel portion. The sheet metal and barrel portion can then be surrounded with molding material with the slug preventing the molding material from flowing into the bore.

RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 08/157,991, now abandoned, filed Nov. 24, 1993, which is a is acontinuation-in-part application of application Ser. No. 92,595, filedJul. 15, 1993, now abandoned, which is a divisional application of Ser.No. 888,580, filed May 26, 1992, now U.S. Pat. No. 5,237,733, which wasa continuation-in-part of Ser. No. 806,172, filed Dec. 12, 1991, nowU.S. Pat. No. 5,146,672, which application was a division of Ser. No.457,060, filed Dec. 26, 1989, now U.S. Pat. No. 5,072,518, which was adivision of Ser. No. 271,123, filed Nov. 14, 1988, now U.S. Pat. No.4,893,394, which was a division of 111,966, filed Oct. 21, 1987, nowU.S. Pat. No. 4,831,698, which was a continuation-in-part of Ser. No.069,804, filed Aug. 17, 1987, now U.S. Pat. No. 4,810,143, which was adivision of Ser. No. 869,507, filed Jun. 2, 1986, now U.S. Pat. No.4,700,470, which was a division of Ser. No. 657,570, filed Oct. 4, 1984,now U.S. Pat. No. 4,610,072, which was a continuation-in-part of Ser.No. 563,833, filed Dec. 21, 1983, now U.S. Pat. No. 4,555,838, which wasa continuation-in-part of Ser. No. 504,074, filed Jun. 14, 1983, nowU.S. Pat. No. 4,543,701 and a continuation-in-part of Ser. No. 485,099,filed Mar. 28, 1983, now U.S. Pat. No. 4,459,073. Ser. No. 504,074 was acontinuation of Ser. No. 229,274, filed Jan. 28, 1981, now abandoned andSer. No. 485,099 was a divisional application of Ser. No. 229,274 filedJan. 28, 1981, now abandoned. Ser. No. 229,274 claims priority to anapplication filed in the Federal Republic of Germany, No. 3,003,908,filed Feb. 2, 1980.

This application also claims priority to an application filed in theFederal Republic of Germany, No. P42 39 584.4, filed Nov. 25, 1992.

BACKGROUND OF INVENTION

The present invention relates to a sheet metal part having at least onenut element introduced by a riveting process. Such sheet metal parts arewell-known in practice and are for example shown in German patentspecification 34 47 006, 34 46 978 and in DE-OS 30 16 675.

In the German patent specification 34 47 006, the nut element is formedas a pierce and rivet nut. For this purpose, the nut element has a nutpart and a tubular pierce and rivet section which merges via anoutwardly directed ring shoulder into the nut part. The nut element isintroduced into the sheet metal by means of a stamping head and, indeed,the sheet metal is first pierced by the pierce and rivet section,whereby a stamped slug arises due to the hollow shape of the pierce andrivet section. The tubular pierce and rivet section is subsequentlydriven through the sheet metal and formed into a turned-over rivetflange at the side of the sheet metal remote from the nut part so thatthe sheet metal is arranged in form-fitted manner between theturned-over rivet flange and the ring shoulder. Raised features or ribsin the region of the ring shoulder of the nut element are pressed intothe sheet metal during this insertion process and form a securityagainst rotation of the nut element, so that on the insertion of a boltthe nut element does not turn relative to the sheet metal.

As can be read in the German patent specification 34 47 006, the stampedslug has to be removed to enable the nut element to be used at all forthe intended purpose. This is achieved in that an injection pin ispushed through the threaded bore of the nut element and thereby pushesthe slug out of the deformed pierce and rivet section.

Starting from a sheet metal part or a method of the initially namedkind, the invention is based on the object of providing a sheet metalpart which is particularly suited to be embedded into an injectionmolded part in that an injection molding composition is injection moldedaround the sheet metal part, with the plastic composition notpenetrating into the thread of the nut element.

It would be possible to satisfy this object in that the nut element isclosed off in the injection molding die on both sides, for example,through confronting wail parts of the injection molding die or throughspecial inserts which lie flush against the two end faces of theinserted nut element. This would, however, lead to restrictions in thelayout of the injection molding die and to considerable extra complexityand cost so that it can also be seen as a general part of the objectunderlying the invention to provide greater freedom in the layout ofinjection molded parts with embedded sheet metal nut elements and alsoto reduce the complexity and cost in realizing the injection molding andthe injection molded part.

BRIEF SUMMARY OF THE INVENTION

In order to satisfy these objects, provision is made in accordance withthe invention, and with a sheet metal part of the initially named kind,that the passage opening of the nut element is closed off by a stampedslug.

The stamped slug is generated with particular advantage during theintroduction of the nut element into the sheet metal and is so deformedthat it at least substantially seals off and is preferably held inform-fitted manner in the pierce and rivet section of the nut element. Asolution would also be conceivable in which a disc, which is preferablygenerated by a stamping process and can thus be considered as a stampedslug, is manufactured in its own right and is subsequently inserted as atype of "cover" into a nut element which has been previously, or issubsequently, riveted to the sheet metal part. In this case, the sheetmetal part is advantageously pre-apertured. This is in particularfrequently necessary with thicker sheet metal parts in the form ofplates or panels when the corresponding plate or panel does not permitthe use of a self-piercing nut. It would also be conceivable tointroduce the stamped slug in this way not into the pierce and rivetsection of the nut element, but rather into the opposite end of the nutelement, so that the bolt which is inserted is not inserted from the nutside into the nut element but rather from the side of the turned-overrivet flange.

Through the closing of the nut element at one end, it is possible toarrange the sheet metal part with the nut element in an injectionmolding die in such a way that either the one wall of the injectionmolding die or a surface of an insert part comes into flush contact withthe nut element at the open side of the thread, whereby the penetrationof the injection molding composition into the thread can be prevented.Since the other respective end of the thread is sealingly closed by thestamped slug, a great degree of freedom results in the layout of theinjection molding die and the shaping of the injection molded part. Thisis so since neither the die wall nor an insert must be present at theend of the nut element closed by the stamped slug in order to preventthe penetration of the injection molding composition into the thread.Special shapes of the sheet metal part with the inserted nut elementwith stamped slug are to be found in the subordinate claims.

The holding of the stamped slug in the nut element by a substantiallyconical formation of the hollow turned-over end of the rivet whichconverges away from the stamped slug at the side of the nut elementremote from the thread, and also an arrangement in which the diameter ofthe stamped slug is greater in the in-built state than the outerdiameter of the thread, are particularly important, since in this waythe stamped slug is held so that it cannot fall out.

An arrangement in which the stamped slug is accommodated in a ring spaceof the stamped slug or of the turned-over rim of the rivet and at leastsubstantially seals off the passage opening of the nut element is alsoparticularly preferred. For this purpose, it is advantageous for thestamped slug to exert a permanent compressive pressure onto the innerwall of the nut element, preferably onto the base of a ring groove whicharises within the pierce and rivet section during the formation of theturned-over rivet flange. In this way, not only is the sealing action ofthe stamped slug reliably ensured, but also no danger of deformationunder the pressure of the injection molding composition is to beexpected. In other respects, a loosening of the nut element during theapplication of torque or bending moments is not to be feared because thestamped slug which exerts a compressive pressure ensures a firmer seatof the nut element.

In manner known, per se raised features, for example in the form of ribsand/or recesses, are provided on the ring shoulder of the nut element,which, after the introduction of the sheet metal element, formcorresponding recesses or raised features of the sheet metal andcooperate with these to form a security against rotation.

The nut element is preferably so secured to the sheet metal part thatthe turned-over rim of the rivet is arranged in a recess of the sheetmetal part. In practice, the recess of the sheet metal extendsapproximately conically and merges in the region of the ring shoulder ofthe nut element into a base surface of the recess which is directedapproximately parallel to the flange, with the passage opening for thepierce and rivet section of the nut element being formed in the basesurface.

The turned-over rivet flange can be sunk within the recess; i.e., theend surface of the rivet flange lies beneath the plane of the sheetmetal at the side of the rivet flange. The turned-over rivet flange canhowever also be flush with this plane or indeed project above the saidplane.

It is particularly favorable with a flush or sunk arrangement of theturned-over rivet flange that only a relatively thin layer of theinjection molded composition must be present at this side of the sheetmetal in order to completely seal off the sheet metal from this side andto protect it from corrosion. In other respects, the recess leads to alocal stiffening of the sheet metal and also increases the loadabilityof the nut element in the sense that higher forces can be introducedfrom the nut element into the sheet metal without destroying theconnection.

The said base of the recess can, for example, merge into the finishedconnection with the nut element into an axially connected collar.Moreover, at least a substantial part of the base and of the collarwhich is optionally formed therein can be arranged in form-fitted mannerin a ring recess of the nut element between the ring shoulder and theturned-over rivet flange.

The invention also includes an injection molded part which is moldedaround the sheet metal part; i.e., the injection molding compositionpartly surrounds the sheet metal part, with the thread of the nutelement being freely accessible from the outer side; i.e. not beingcovered over by the injection molded composition and serving to receivea screwed in part.

An example for the injection molded part would be the sole of a sportingshoe, with the nut element or nut elements being formed for the mountingof parts, such as spikes or studs which are, in particular,interchangeable. In this example, one can select a corrugated orperforated piece of spring steel for the sheet metal part, which ensuresa flexibility of the sole. By way of example, the sole could be made ofa spring-hard steel strip of high flexibility with a corrugated form(sinus wave) with an amplitude of(cat 3 mm and a field width of 8 mm.The injection molding composition is in this case realized as a plasticor opposition.

Another example for the injection molded part would be a plasticcoachwork part with the nut element or the nut elements, for example,serving for the mounting of a hinge or for securing to other coachworkparts.

The invention also includes a method of manufacturing a sheet metal partwith at least one nut element secured to the sheet metal part.

An important further development of this method lies in the fact thatthe sheet metal part with at least one nut element secured therein isremoved from the piercing and riveting press and is inserted into aninjection molding die with the thread of the nut element, or of each nutelement, being closed at one side by the stamped slug and at the otherside by contact of the end face of the nut part containing the threadagainst a wall part of the injection molding die, or against a partprojecting into it, whereby the injection molding composition cannotpenetrate into the thread. In other respects, positioning pins in theinjection molding die can press against the stamped slug so that therespective nut elements are held against the wall part (or against aninsert part of the injection molding die), with the turned-over rivetflange, which surrounds the positioning pins, preferably simultaneouslycooperating with the positioning pins to ensure alignment of the sheetmetal part in the injection molding die.

The invention will now be explained in more detail with reference to thedrawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 a partial cross-section through a stamping head in the initialstage of a method of introducing a nut element into a sheet metal partby piercing and riveting;

FIGS. 2 to 4 further stages of the piercing and riveting method;

FIG. 5 a representation corresponding to that of FIG. 4 of the end stageof a modified riveting process with a somewhat different procedure;

FIG. 6 a perspective partial illustration of a sporting shoe withspikes;

FIG. 7 a partial cross-section through the sole of the sporting shoe ofFIG. 6 in the plane VII--VII in the region of one spike; and

FIG. 8 an enlarged illustration of a section of a sheet metal part withinserted nut element in an only partially illustrated injection moldingdie for the introduction of the injection molding composition, whereinthe injection molded part of FIG. 8 could also be used for the sole of asporting shoe in accordance with FIG. 6 or FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a section through a stamping head 10, which, in general, isformed in accordance with the stamping head of the German patentspecification 34 46 978 and, above all, in accordance with the Germanpatent specification 34 47 006 and which can be built into a stampingand/or embossing press with oppositely disposed plates which are movablerelative to one another. FIG. 1 discloses the stamping head built intothe upper press plate, it could however be built into the lower pressplate or into an intermediate plate in just the same way.

The stamping head 10 contains a ram unit 12, which is able to stamp afastener nut element 14 with a pierce and rivet section or panel portion16 through a panel 18, a piece of sheet metal 18 is disclosed, which isheld during the stamping movement between the stamping head 10 and thedie button 20 as will later be explained in detail. The stamping head 10is provided with a supply device (not shown) which is able to feedindividual nut elements 14 into the stamping head and to bring them intothe working position of FIG. 1. Such feed devices are known from thenamed prior art and will thus not be described here. Although the nutelement 14 appears to hang in the air in FIG. 1 it is in practice heldby resilient fingers or the like in the stamping head by friction sothat it does not drop downwardly under its own weight.

As is evident from this drawing, above all from the cross-sectionaldrawing at the left hand side of the centerline 13 of the ram unit 12,the nut element 14 has a nut part or body portion 15 with an innerthread 24, and also the tubular pierce and rivet section 16 whichadjoins the nut part and which merges via a radially outwardly directedring shoulder 26 into the nut part. Ribs or noses 28 are provided onthis ring shoulder which form a security against rotation. The action ofthese ribs or noses will be described later. The pierce and rivetsection 16 of the nut element 14 has a ring-like hollow cavity or bore29 which is coaxially aligned with the passage opening of the thread 24and has at the lower end a rounded impact and drawing edge 32 at the endface of the pierce and rivet section.

At the side of the sheet metal part 18 remote from the stamping head 10,there is located a die button 20 which contains a cylindrical insert 30which can also be termed a press mandrel. In this embodiment, the insertis non-displaceably but interchangeably arranged in the correspondingreceiving bore 31 of the die button 20. The reference numeral 20 thusrepresents the actual die button and contains the insert. In someembodiments the die button 20 and the insert 30 are made in one piece.Which embodiment comes into use is ultimately a question of the costrelated to the given application. Depending on the sheet material to beprocessed, the insert 30 is subjected to a greater or lesser degree ofwear. It can thus be sensible to make the insert 30 as an exchangeablepart when a high degree of wear is to be expected.

The axial end 33 of the insert 30 facing the sheet metal 18 has asmaller diameter than the guide or body part 34 of the insert and formstogether with the die button 20 surrounding the insert a U-shaped ringgroove or channel 36 which is open in the direction towards the sheetmetal part 18. The ring groove forms a type of a recess the shape ofwhich can be described as a half-toroid. The radially inner boundary ofthe groove 36 is formed by a rounded ring shoulder 38 of the insertwhich merges from the axial end 32 with the smaller diameter into thebody part 34 via a gently rounded continuous transition, with thistransition being completed at the axial position or ring edge 40 of theinsert. The die button 20 has a ring-shaped recess 42 which correspondsto the shape of the ring shoulder 38 in an at least substantiallymirror-image manner. The lowest point 44 of the ring-shaped recess 42 ofthe die button 20 however lies in the representation of FIG. 1fractionally below the lowest point 46 of the U-shaped ring shoulder 38of the insert 30, or is at most aligned with the corresponding ring edge40.

The ting recess 42 of the die button 20 is continued in the embodimentof FIGS. 1 to 4 beyond the actual end face 48 of the insert and mergesvia a rounded ring shoulder 50 into a shallow ring-like region 52. Thecontour of the die button then merges via a further rounded ringshoulder 54 into a wall 56 which borders conically downwardly (in FIGS.1 to 5) and rounds out at approximately the level of the line 40 via afurther ring shoulder 58 into a surface 60 parallel to the sheet metal18. This surface 60 then merges into the actual press surface of thetool which is used for the forming of the lower side of the sheet metalpart 18.

The due button thus forms an annular raised portion around the insertwhich is characterized by the general reference numeral 64. As shown bythe continuous centerline 13 the insert is coaxially aligned with thenut element 14 and the ram unit 12.

The stamping head 10 is provided with a circular recess 66 in a shapewhich is complementary to the shape of the outer boundary of the annularraised portion 64 of the due button, but which is, however, greater indiameter by about twice the thickness of the sheet metal pan 18, so thaton closing of the press space is provided for the sheet metal betweenthe ring recess 66 and the annular raised portion 64. In other words therecess 66 has a cortically extending wall pan 68 which divergesdownwardly and which merges via a ring shoulder 60 into a ring surface72 parallel to the plane of the sheet metal 18. The ring surface 72 canthen merge in correspondence with the ring surface 60 into the actualpress surface of the tool, at least when the press is closed.

The actual end face 48 of the insert 30 has a plateau region 74 at thecenter which merges via an oblique preferably slightly arched chamfer 75into an annular recessed shoulder 76. The shoulder 76 in turn mergesinto a steep wall section 78 of the ring shoulder 38 at the edge 80.

It is furthermore evident from FIG. 1 that the rounded impact anddrawing edge 32 of the pierce and rivet section of the nut element hasan oblique chamfer 82 at the radially inner side, for example at anangle to the centerline 13 of approximately 45°, and merges at theradially outer side via a gentle curve 84 into a cylindrical outer wallsection 86 parallel to the cylindrical inner wall of the pierce andrivet section.

The cylindrical wall section 86 merges at approximately half height intoa conically upwardly diverging section 88 which subsequently merges viaa rounded portion into the ring shoulder 26. One notes also that thecylindrical inner wall 90 of the nut element has a larger diameter thanthe thread 24. Finally, one sees from FIG. 1 a punch insert or punch 92which is fixedly arranged in the ram 12 and extends with radialclearance through the thread 24. As an alternative to this, adisplacement movement of the punch insert 92 could be permitted, forexample to facilitate the introduction of the individual nut elements14, or for technical reasons during the later occurring movement of theram unit 12 in the direction of the matrix insert. In this example thelower end of the punch insert 92 is of hexagonal shape and merges via aslight ring chamfer 94 into a central surface 96 parallel of the sheetmetal pan 18. Between the chamfer 94 and the outer wall of the punchinsert 92 there is an annular rounded Portion 98.

The insertion of the nut element into the sheet metal part takes placeat the same time as the sheet metal part is shaped in the press, as willnow be described with reference to FIG. 1 and the further FIGS. 2, 3 and4.

FIG. 1 shows an initial stage after the insertion of the sheet metal 18,before the press has completely closed; i.e., the upper press plate hasbeen pressed down onto the lower press plate. Shortly before the closingmovement of the press, a nut element is introduced beneath the ram 12via a supply device and adopts the position shown in FIG. 1. The designof the supply head is adequately known from other documents, for examplefrom the documents initially named here, and will not be explainedfurther.

The stamping head is customarily restrictedly displaceably journaled inthe press plate and is biased in the direction towards the sheet metalpart. The ram unit is however coupled to the press plate at least duringthe closing movement. During the closing movement of the press thestamping head moves downwardly in the direction of the die button, andthe ram 12 simultaneously moves downwardly so that the pierce end 32 ofthe pierce and rivet section of the nut element first indents the sheetmetal under the pressure of the ram as is evident in FIG. 2. Through theindentation, the sheet metal part is held in the press againsttransverse displacement. At this stage, the stamping head 10, but not,however, the ram unit, moves back somewhat, while the closing movementof the press is continued. The nut element exerts a shearing action onthe sheet metal under the pressure of the ram unit in conjunction withthe fixed end of the insert 30 and cuts a circular stamped slug 100 outof the sheet metal.

FIG. 2 shows precisely the position of the tool in which the stampedslug 100 is formed. One notes that the stamped slug which is to beattributed on middle, which is to be attributed on the one hand to theshaping of the end face of the insert 30 and on the other end to theshearing action between the stamp and rivet section of the nut elementand the insert 30. Stated more precisely, this arching of the stampedslug 100 results from the action of the cutting surface 82 of the pierceand rivet section and the cutting edge 33 of the insert 30, as alreadyexplained above.

Through the contact of the sheet metal with the ring surface 52, andalso with the rounded portion 70 at the transition to the conical wall68 of the ring recess into the horizontal surface 72, the saidindentation (i.e., a first deformation of the sheet metal 18) occurs,which is then continued in accordance with FIG. 3 during the furtherclosing movement of the press 10. The ram unit 12 is also pressedfurther downwardly by this movement so that the pierce and rivet sectionof the nut element is driven through the hole which has arisen throughthe formation of the stamped slug. As a result of the ring shoulder 38,which acts as a rolling surface, the pierce and rivet section isdeflected outwardly so that the impact and drawing edge 32 which is nowsomewhat deformed is now located in the part of the ring groove 36 whichis formed by the die button 20.

Since the point 46 of the insert lies fractionally higher of the point44, it is ensured, even with unfavorable tolerances, that no ring stepis formed at this position which could hinder the outwardly directedmovement of the impact and drawing edge of the pierce and rivet sectionof the nut element.

Since the pierce and rivet section of the nut element is driven throughthe hole formed in the sheet metal by the cutting out of the stampedslug a type of wedge action arises here which drives the sheet metaldownwardly and outwardly, so that the sheet metal, as shown in FIG. 3,has a pronounced conical recess 108. As the upper press plate has beenpressed further downwardly the sheet metal also has a more pronouncedring-like raised portion 110 above the ring-like surface 52 of the diebutton 20. It should be pointed out that to manufacture this ring-likeraised feature not inconsiderable forces are necessary which must besupplied by the stamping head 10.

The stamped slug 100 is, as a result of the lowering of the stampinghead, driven further into the cylindrical hollow cavity 90 of the pierceand rivet section of the nut element but does not yet however contactthe end face of the punch 92.

The downwardly directed movement of the stamping head or of the upperpart of the press is continued and now not only presses the ram unit butalso the stamping head, which has reached the end of its path ofdisplacement, downwardly until the end stage of FIG. 4 is achieved. Ascan be seen in particular from the partly cut away left hand side of thedrawing of FIG. 4, the pierce and rivet section 16 of the nut element isnow formed by the U-shaped groove into a complete turned-over rivetflange which has an upwardly directed U-shaped ring recess 114 in whichthe material of the sheet metal around the hole produced by the cuttingout of the stamped slug is received in the form of a downwardly directedcylindrical collar 116. Through the cooperation of the stamping head andalso the die button, the sheet metal merges via a ring shoulder 118 intoa conical downwardly broadening part 120, which subsequently merges intoa flat region 122 of the sheet metal, the plane of which is determinedby the surface 66 of the die button and the surface 72 of the stampinghead. As the nut element has now been completely downwardly driven thenoses or ribs 28 are located in corresponding recesses of the ringshoulder 118 of the sheet metal which have been formed by the downwardpressing of the noses 28 and an enhanced security against rotationarises here which prevents turning of the nut element during later use.

The upwardly arched stamped slug in FIGS. 2 and 3 is first pressed flatand indented; i.e., compressed in this end stage by the end face of thepunch, so that the material is pressed outwardly. When the punch 92 isdisplaceably journaled relative to the ram unit, and for example biasedforwardly by a strong spring, then it can deflect rearwardly somewhatduring the compression of the stamped slug. The outwardly directedmovement of the material of the stamped slug resulting from thecompressive action leads to a permanent compressive pressure between theouter ring edge 124 of the stamped slug and the inner wall of the pierceand rivet section 16 of the nut element. Furthermore, the inner wall ofthe pierce and rivet section is deformed by this compressive pressure;i.e., by the compression of the stamped slug, to a slightly downwardlyconverging surface so that the stamped slug cannot drop out downwardly.Through the compressive pressure it is also ensured that a very goodseal is present here. The stamped slug can thus not be lost downwardly.It can however also not be lost upwardly because the thread 24 has asubstantially smaller diameter than the wall part 124 of the pierce andrivet section against which the outer edge of the stamped slug is insealing contact. After the opening of the press the sheet metal partwith the pierced and riveted nut element can be removed from the pressand conveyed out of the press.

In accordance with a first method variant, the manufacturing method ofthe sheet metal part 18 with the inserted nut element finishes at thisstage on taking the sheet metal part out of the press.

Although the previous process has only been concerned with the insertionof a single nut element, a plurality of nut elements can bestraightforwardly provided at different locations of the sheet metalpart in the same way and means with one stroke of the press. Thepiercing of the sheet metal part by the nut element can however alsotake place differently than is described here. For example it isconceivable that the ram unit could be pressed downwardly via a strokemovement carried out separately from the closing movement of the press.

Instead of terminating the method of manufacture with the opening of thepress after the manufacturing step of FIG. 4, it can be advantageous tocarry out a further manufacturing step as is shown in FIG. 5. Themanufacturing step of FIG. 5 takes place with different tools than areshown for FIGS. 1 to 4. This manufacturing step of FIG. 5 can take placein a quite different press installation and can however also be carriedout as a further step in a further station of the same pressinstallation as was used for carrying out the method steps of FIGS. 1 to4; i.e., the press installation is laid out to use sequential steptooling.

FIG. 5 shows several possible method variants in one drawing. FIG. 5 inparticular shows a possibility of more reliably framing the stamped slugwithin the nut element. Furthermore, FIG. 5 shows the possibility ofpressing the rivet flange 112 flat. This is on the one hand interestingwhen, for example, the end face of the turned-over rivet flange 112should lie within the recess 120 of the sheet metal part 18, or when, ina separate process the stamped slug 100 is not to be inserted at theposition shown in FIG. 5, but rather in a ring space at the other end ofthe nut. In the latter case, the bolt which cooperates with the nutelement should be introduced from the side of the turned-over rivetflange 112 and would customarily press a different sheet metal componentagainst the turned-over rivet flange 112. In this case, the planardesign of the rivet flange 112 leads to an enlargement of the surfacetransferring the clamping forces whereby an excessive surface pressurebetween the rivet flange 112 and the sheet metal pan to be screwed oncan be avoided, so that plastic deformation of the sheet metal pan or ofthe rivet flange 112, or the settling effects of these pans as a resultof excessive surface pressure need no longer be feared.

In the embodiment of FIG. 5, the die button 20 has a substantiallyplanar surface 60 without a pronounced annular raised portion 64. Inplace of this the surface of the die button 20 which faces the sheetmetal simply has a ring-shaped surface 130 which merges via a small step132 into the planar surface 60. The ring surface 130 is parallel to thesurface 60; i.e., to the plane of the inserted piece of sheet metal 18of the earlier station (where the method steps were carded out inaccordance with FIGS. 1 to 4). The insert 30 has a substantiallycylindrical shape and merely has a rounded undercut 134 at the end facewith the rounded undercut terminating in a planar surface 74 arrangedperpendicular to the center line 13.

The ram unit 12 in this embodiment has no centrally arranged punch 92 asin the ram unit of the earlier station. The stamped slug 100 which iscut out from the sheet metal pan 18, and which is arranged in FIG. 4beneath the thread 24, is pushed upwardly under the action of the nowpresent insert 30 until it abuts at the upper side against a ringshoulder 136 which is located directly beneath the thread 24 of the nutelement 14.

The ring edge 138 of the insert 30 has a diameter at the position wherethe right cylindrical surface 140 of the insert merges into the roundedundercut 134 which is greater than the inner diameter of the cylindricalhollow cavity 90 in some regions of the pierce and rivet section 16 andwhich functions as a kind of shearing and reforming tool while the nutelement 14 is pressed downwardly under the action of the ram unit 14.During this, an annular rim 142 is formed from the material of thepierce and rivet section 19 of the nut element. The result is that thestamped slug 100 is held under permanent compressive pressure inform-locked and sealed manner in a ring groove 144 with this ring groove144 being formed in the upper region by the ring shoulder 136 of the nutelement and in the lower region by the annular rim 142.

Since the die button 20 has the planar ring surface 130 around theinsert 30, the rounded end face around the pierce and rivet section 16of the nut element as obtained in accordance with the method step ofFIG. 4 is pressed flat into a planar ring surface 152.

In this embodiment, it is not necessary to provide a punch insert 92,however, a punch insert of this kind can be selected at will if itshould turn out in practice that a counter-pressure on the upper surfaceof the stamped slug 100 in FIG. 4 would be useful during the securing ofthe stamped slug 100.

It is also entirely possible to insert a circular disc which has beenstamped out from a piece of sheet metal and which has the size of thestamped slug 100 using a punch with the form of the insert 30 of FIG. 5prior to inserting the nut element 14 into the sheet metal part 18;i.e., to insert the slug 100 in a previous working step. A method ofthis kind is, for example, advantageous when the sheet metal part 18 isrelatively thick, for example in the range from 3 to 7 mm which makesthe use of self-piercing nut elements 14 difficult. With a relativelythick piece of sheet metal of this kind, the sheet metal 18 can bepre-apertured either with a special stamping tool or by a drillingprocess, so that the nut element is inserted into the previously formedhole and then riveted to the sheet metal part 18, for example in a pressprocess as previously mentioned.

It should be pointed out here, that during the provision of a stampedslug in the riveting section, the diameter of the insert 30 (i.e., thediameter at the edge 134) should be selected to be slightly larger priorto insertion of the nut element than the diameter of the undeformedrivet section 16, so that sufficient material is present in order toform the annular rim 42.

The tool of FIG. 5 can also be used, optionally with smallmodifications, to insert a "foreign" stamped slug 100 into the end ofthe nut element remote from the pierce and rivet section. For thispurpose, the corresponding end face of the nut element should beprovided with a tubular projection similar to the pierce and rivetsection, but somewhat shorter, whereby the matrix insert can then bepressed downwardly from above in order to press material downwardly fromthe wall of the tubular projection in order to generate a rimcorresponding to the annular rim 142 which secures the stamped slug atthis end face of the nut element. Following the formation of nut elementin this way, the nut element can be stamped into a piece of sheet metal18 in accordance with the method of FIGS. 1 to 4 and riveted to thelatter, with the ram insert 92 then being omitted. As a subsequentmethod step, the turned-over rivet flange can also be pressed flat inaccordance with FIG. 5, which would be entirely preferred here, since inthis embodiment, the bolt which is inserted into the nut element isscrewed in from the side of the rivet flange, will serve to press apiece of sheet metal against the flat end face of the rivet flange.

The use of the stamp with approximately the shape of the insert 30 inFIG. 5 has the advantage that the stamped slug 100 is firmly anchored inthe annular groove 144 of the nut element 14 and that it cannot be lostunder any circumstances, which is very important when the nut elementsare already provided with such stamped slugs from the works of themanufacturer. It would namely be very undesirable for a stamped slug tobe occasionally lost from nut elements with previously inserted stampedslugs 100, since this could cause catastrophic effects during thesubsequent handling of the nut element. If, for example, a stamped slug100 is lost when inserting a nut element into a press, then the loststamped slug 100 could damage the sheet metal part or also the tool. Ifit is lost from the sheet metal part, then during the subsequent moldingprocess, the molding composition would enter into the thread and thecomponent would have to be scrapped. The flowing of the injectionmolding composition through the thread can also lead to the injectionmolding installation being contaminated or damaged.

When using nut elements with previously inserted stamped slugs, thepossibility also exists of manufacturing the stamped slug 100 from athinner piece of sheet metal than the sheet metal 18 into which the nutelement is to be inserted.

FIG. 6 shows an example of the use of the present invention for the sole200 of a sporting shoe or of a golf shoe. The sole 200 consists of aplastic composition 201, or of rubber and has in its interior, as isevident from FIG. 7, a sheet metal part 18 which is provided with nutelements 14 (of which only one element can be seen in FIG. 7) which wereinserted in accordance with the previously described method of FIGS. 1to 4. These nut elements 14 form threaded mounts for spikes or studs 202which are screwed into the respective nut elements. In distinction tothe previously described methods, no pronounced recessing of the sheetmetal is provided in this example in the region of the individual nutelements. This requires a somewhat modified shape of the upper side ofthe and also of the lower side of the stamping head.

The way in which the sheet metal part with the inserted nut elements isembedded in the plastic composition of the sole 200 is evident from FIG.8.

FIG. 8 shows only one part of an injection molding die in cross-sectionhaving upper and lower die parts 300 and 302 which fit together at apartition joint 304 and form respective hollow die cavities 306 and 308.The sheet metal part 18 with the inserted nut elements 14, of which onlysome are shown, sit in the hollow cavity of the injection molding dieand are supported on pins, such as for example 310, which in thisexample are arranged beneath the respective stamped slugs 100. In thisexample, that it cover rim 112 of the rivet satisfies a double-functionin that it cooperates with the pins 310 and brings about a centering ofthe sheet metal part 18 in the injection molding die. If necessary,other centering devices can however also be provided. Above the nut partof the nut element 14 there is located a further die insert in the formof a pin 312 with a cylindrical head 314 which is arranged above the nutpart and contacts the end face 310 of the nut part. The head 314 has adiameter which is admittedly greater than the core diameter of thethread, but is however smaller than the outer diameter of the nut pan.As the stamped slug 100 is somewhat resilient, this design enablescomplete closing of the two halves of the injection molding die, even ifthe tolerances of the pins 310 and 312 should be somewhat unfavorable.After the closing of the injection molding die, the injection moldingcomposition is injected into the die. It flows into all hollow cavitiesof the injection molding die; i.e., into the regions shown there bycross-hatching in FIG. 8. One notes that the injection moldingcomposition surrounds a part of the other end surface of the nut part ofthe nut element 14. This has the advantage in a shoe sole that, on theone hand, penetration of moisture around of the nut part is made moredifficult and, on the other hand, as shown in FIG. 7, a stud or spikecan be so screwed in that a collar part 204 compresses the injectionmolding composition present between the stud and the nut element. Thisnot only brings about better sealing, but rather also a security againstrotation of the respective stud or spikes so that these cannot be lost.

The method of manufacturing the sole of a golf shoe will now be brieflydescribed once again.

With a golf shoe sole, the sheet metal part can consist of 0,3 mmspring-hard strip steel of high flexibility. This strip steel isdeformed simultaneously with the insertion of the nut elements in thepress to a corrugated shape (sinewave) through corresponding profilingof the press plates. The waveform of the profiled sheet metal has anamplitude of ca. 3 mm and a field width (wavelength) of ca. 8 mm. A highelasticity of the spring-hard shoe sole is achieved by this profiling.The sheet metal part is then simultaneously stamped out at its outerperiphery in the press so that it receives the shape of a foot print.

In order to receive the already described thread bearing spikes, the nutelements must be so secured to the formed sheet metal part (i.e., to thesole of the shoe) that they can withstand the deformations which occurduring the course of each step (rolling off of the sole of the shoe onthe ground).

At the point of connection nut/sole of the shoe, translatory movementsaccordingly occur between the nut elements and the sheet metal sole ofthe shoe. Through the described embodiment of the turned-over rim of therivet with the measures providing security against rotation, it isensured that these transnational movements do not exert any notcheffects on the sheet metal of the shoe sole. The assembled molded sheetmetal part comprising the nuts and the metal sole of the shoe isembedded into a plastic sole and is surrounded on all sides by thisplastic or rubber material. During this, the inserted stamped slugsensure that the threaded rear side of the nuts are so closed that noplastic or rubber material can penetrate into the threaded bore.

As explained, the thread entry is closed off by corresponding sealingmeasures in the plastic or rubber molding tool, such as-through the pins312 in the example of FIG. 8.

The sealing at the rear side of the thread is achieved, as stated, inthat the pierce and rivet nut is not introduced into a prestampedopenings of the steel sole of the golf shoe but rather in aself-piercing manner. As explained in detail above, the stamped slugwhich is thereby cut out from the hole is so positioned by a specialtool punch construction in the turned-over rivet flange that itfunctions as a sealing cover against the penetration of theplastic/caoutchouc composition.

The installation steps are in detail:

a) In a suitable lower part of the tool (corresponding to the shape ofthe shoe sole), there are provided as many receiving cavities as thereare nuts;

b) In the upper part of the tool, there is in the same number of thestamping buttons for the stamping in and the turning over of the rivetportions of the nuts, with the stamping buttons being located exactlyabove the receiving cavities for the nuts;

c) A fastener such as, for example RSF nut (obtainable from the companyProfil), is positioned in each receiving cavity in the lower part bysuitable supply means, with the pierce and rivet section pointingupwardly;

d) A sheet metal part which is non-apertured, but which has beenpre-flattened,is placed on the nut elements, with the sheet metal partbeing held in form-fitted manner by the contour of the receiving mountof the tool;

e) Suitable checking measures ensure that the fasteners and the sheetmetal part are in the installation position;

f) As the upper part of the tool passes through the lower dead point thenut elements have cut through the sheet metal part via the cutting andpiercing action. A circular, ring-like, turned-over rivet flange isformed at each nut which holds the punched out slug through a relativelyhigh clamping action (arching effect) as a cover in the pierce and rivetsection and closes the rearward opening of the nut. After the upwardtravel of the upper part of the tool and removal of the shoe sole withthe stamped-in and riveted-in nuts the methods steps for the assembly ofthe assembled component are terminated, whereupon the latter can beplaced in an injection molding die and the embedding in the injectionmolding composition; i.e., in the selected plastic/caoutchouk materialcan take place;

g) Thereafter, the sole of the shoe together with the upper part of theshoe is formed into a finished shoe with subsequent screwing in of thespikes or studs.

Finally, it should be pointed out that the nut elements need notnecessarily be of round cross-section, polygonal cross-sections are forexample also entirely possible. It is also not absolutely essential thatthe nut elements must have threads, they could for example also havebayonet mounts. They should, in general, be considered to be hollowfastener elements.

I claim:
 1. A method of making a molded part having a sheet metalportion and at least one fastener coupled to the sheet metal portioncomprising the steps of:a) providing a fastener having a body portionand an annular barrel portion extending from the body portion, thebarrel portion having an opening and the body portion having a free openend and a bore extending therethrough in generally coaxial alignmentwith the opening in the barrel portion: b) locating the fasteneradjacent the sheet metal with the barrel portion free end facing saidsheet metal; c) biasing the fastener barrel portion free end against thesheet metal; d) driving the barrel portion free end into the sheetmetal, piercing the sheet metal and forming a slug from the sheet metal;e) deforming the barrel portion free end radially outwardly, inmechanical interlocking relation with said panel; f) wedging the sluginto the opening of the barrel portion; g) surrounding the sheet metaland the opening of the barrel portion with molding material with theslug preventing said molding material from flowing into said bore. 2.The method of claim 1, including the step of internally threading saidbore.
 3. The method of claim 1, wherein said opening in said barrelportion has an inner diameter that is greater than the inner diameter ofsaid bore forming an offset between said opening in said barrel and saidbore, said method including the step of forming an inwardly extendinglip within said barrel portion, said slug being retained between saidlip and said offset.
 4. The method of claim 3, wherein said slug isremovably secured within said barrel.
 5. The method of claim 1, whereinsaid fastener includes a shoulder extending radially outwardly from theouter surface of said fastener, generally between said body portion andsaid barrel portion, said shoulder including ribs, said method includingthe step of deforming said sheet metal adjacent said ribs definingraised features, said raised features operating with said ribs to resistrotation of said fastener.
 6. The molded part of claim 1, including thestep of deforming said sheet metal to form a recess; anddeforming saidbarrel portion in said recess.